18. s = 5r^2 + 7......making r the subject
s - 7 = 5r^2
(s - 7) / 5 = r^2...by taking the sqrt of both sides, it eliminates the ^2
( sqrt (s-7)/5) = r
19. h = ut - 1/2gt^2....u = 100, t = 1 4/5(or 9/5)...g = 6.4
h = (100)(9/5) - 1/2(6.4)(9/5^2)
h = 180 - 1/2(6.4)(3.24)
h = 180 - 3.2(3.24)
h = 180 - 10.368
h = 169.632 or 169 79/125
20. sorry..do not know this one
Answer:
4.24
Step-by-step explanation:
First, let's set up the equation: 
Next, clear the fraction by multiplying both sides by 2:
Then, subtract 2 from both sides: 
Finally, take a square root of both sides and round: 
(Rounded to the nearest hundredth) 4.24
Answer:
A) 9 and 15.
Step-by-step explanation:
First, let's see what each number's factor is:
A)
9 : 1, 3 & 9
15 : 1, 3, 5 & 15
B)
6 : 1, 2, 3 & 6
10 : 1, 2, 5 & 10
C)
8 : 1, 2, 4 & 8
12 : 1, 2, 3, 4, 6 & 12
Therefore, The number 3 is a common factor of A) 9 and 15.
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9514 1404 393
Answer:
11.5 m
Step-by-step explanation:
The fact that the figures are similar means the side lengths are proportional:
RS/QT = BC/AD
RS/(7 m) = (2.3 m)/(1.4 m)
RS = (7 m)(2.3/1.4) . . . . . . multiply by 7 m
RS = 11.5 m
